You already know what I think. I think you need to stop thinking and start working.
If you are running A4F long arms, they already have caster correction built into the arms. This is unfortunate, because it's backwards from the direction you need. But they are nice arms, and if they are already on the Bronco, then use them.
Step 1. Cut off your factory wedges. Use an angle grinder with a 1/16x4.5 inch cut off wheel. One slice thru each weld. Save the wedges, because they cost $100 and there's nothing wrong with them.
Step 2. Figure out what you are going to do with your Bronco. Are you EVER going to lower it again? Are you EVER going to go taller? After you do the mental gymnastics, go buy a set of 2 degree poly bushings.
Step 3. Clean up your housing. Now is a really good time to grind off the weld for the inner C. With the wedges out of the way, it makes for easier grinding.
Step 4. Figure out your ride height. You said that you are 4.5 lift, but that's just a marketing number. Measure the distance from your axle tube top to the frame. It had better be 11.5 inches. Go cut a 2x4 that's 11.5 inches long. (or whatever number you actually are running.) Use it as a gap gage for height. You don't want anything to do with springs or coil cups at this point. (this should actually be step 0...)
Step 5. Install the 2 degree bushings on to your radius arms with your unwelded wedges. Install them as they were intended so that when this thing actually gets to an alignment shop, you will still have the ability for some adjustability. Clamp the c-cap bolts until they are snug. Install the front driveshaft. Roll the pinion up until the u-joint is exactly perfect. with the pinion pointing in line with the driveshaft. Measure the driveshaft angle. Which is also the pinion angle, which is also the diff cover angle. Take that number, and write it on the wall in your shop.
Step 6. I usually tack weld the wedges to the tubes at this juncture, (and I usually end up cooking my c-bushings a little.) It's ugly, and I usually regret it. But if you don't have a jig...it's hard to get the wedges perfect. A little tack will go a long way to making sure you don't introduce the "bronco lean"
Step 7. Install your inner C's. Rotate them to give yourself 7 degrees of Positive Caster. 6 if you like. Go back and answer step 2 again, convince yourself that 4.5 is the right height, and then set your caster. Put a tiny bit more positive caster in the Drivers side. Tack the inner C's.
Step 8 Remove the axle, and weld it. Step back and admire your work. (you will note, at this juncture...that you have done all of the work necessary to install a welded wedge High Pinion, except that you have sacrificed a perfectly good Early Bronco 44...)
Your situation reminds me of the story of the man who went to the restroom, and after using the urinal...accidentally dropped a quarter from his pocket into the urinal. He stood back, thought about it, and then took a $20 bill from his wallet and threw it into the urinal. He then reached into the toilet and pulled out the quarter, and the $20. The guy next to him asked "Why did you throw that $20 into the toilet?"
They guy replied: "Well, I wasn't going to reach in there for a lousy quarter..."
Lets hope he gets the job done
